The lower esophageal sphincter (LES) is a ring of muscle at the entrance to the stomach. If functioning normally, the LES closes as soon as food passes through it. With improper closure, acid produced by the stomach may move up into the esophagus. This may cause symptoms such as heartburn. If these symptoms happen at a frequency greater than twice a week, it is classified as acid reflux disease or gastroesophageal reflux disease (GERD).
Gastroesophageal reflux disease is common, occurring in 30-40% of adults in the USA. Current management is pharmacologically done with proton pump inhibitors. The use of proton pump inhibitors is known to result in maldigestion, causing incomplete (1) digestion of proteins by acid proteases, (2) incomplete or lack of solubilization essential minerals such as calcium and magnesium, (3) diarrhea caused by bacteria such as Clostridium difficile, (4) increased risk of bone fracture and (5) impaired absorption of vitamin B12.